ELECTROSTATIC DISCHARGE PROTECTION DEVICE
An electrostatic discharge protection device comprising a multi-finger gate, a first lightly doped region of a second conductivity, a first heavily doped region of the second conductivity, and a second lightly doped region of the second conductivity. The multi-finger gate comprises a plurality of fingers mutually connected in parallel over an active region of a first conductivity. The first lightly doped region of a second conductivity is disposed in the semiconductor substrate and between two of the fingers. The first heavily doped region of the second conductivity is disposed in the first lightly doped region of the second conductivity. The second lightly doped region of the second conductivity is beneath and adjoins the first lightly doped region of the second conductivity.
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1. Field of the Invention
The invention relates to electrostatic discharge protection and, in particular, to an electrostatic discharge protection device applied in high voltage input/output (I/O).
2. Description of the Related Art
In
An embodiment of an electrostatic discharge protection device comprises a multi-finger gate, a first lightly doped region of a second conductivity, a first heavily doped region of the second conductivity, and a second lightly doped region of the second conductivity. The multi-finger gate comprises a plurality of fingers mutually connected in parallel over an active region of a first conductivity. The first lightly doped region of a second conductivity is disposed in the semiconductor substrate and between two of the fingers. The first heavily doped region of the second conductivity is disposed in the first lightly doped region of the second conductivity. The second lightly doped region of the second conductivity is beneath and adjoins the first lightly doped region of the second conductivity.
The invention provides an electrostatic discharge device with double diffused drain (DDD) structure applied in high voltage input/output (I/O) in high voltage technology. A lightly doped region of the same conductivity as the double diffused drain (DDD) is formed adjoining the double diffused drain. As a result, current accumulating near the drain junction is suppressed such that ESD protection device is more robust.
A detailed description is given in the following embodiments with reference to the accompanying drawings.
The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
As shown in
In
Table I shows experimental results of ESD testing for conventional DDD NMOS devices and DDD NMOS devices according to an embodiment of the invention. The ESD tests are respectively carried out for human body mode (HBM) and machine mode (MM). IT2 is a trigger current of second breakdown of the ESD protection devices in a transmission line pulse (TLP) ESD test. X is the distance between edges of the N-type drain region and the fingers of the poly gate of the ESD protection devices and TW total width of the ESD protection devices. The table I shows that the trigger current of second breakdown of the ESD protection devices with an additional N-well exceeds 1.4 A, higher than ESD protection devices without the additional N-well. In addition, the ESD protection devices with the additional N-well pass ESD pulse test of HBM at 2 KV and MM at 200V, indicating that the ESD protection devices with the additional N-well provide superior ESD performance.
The invention provides an electrostatic discharge device with double diffused drain (DDD) structure applied in high voltage input/output (I/O). A lightly doped region of the same conductivity as the double diffused drain (DDD) is formed adjoining the double diffused drain. As a result, current accumulating near the drain junction is suppressed such that ESD protection device is more robust.
While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements as would be apparent to those skilled in the art. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
Claims
1. An An integrated circuit device, comprising:
- a multi-finger gate comprising a plurality of fingers mutually connected in parallel over an active region of a first conductivity;
- a first lightly doped region of a second conductivity in the active region between two of the fingers;
- a first heavily doped region of the second conductivity disposed in the first lightly doped region of the second conductivity; and
- a second lightly doped region of the second conductivity beneath and adjoining the first lightly doped region of the second conductivity.
2. The electrostatic discharge protection device as claimed in claim 1, wherein the active region of the first conductivity is a well region or a semiconductor substrate of the first conductivity.
3. The electrostatic discharge protection device as claimed in claim 1, further comprising two second heavily doped regions of the second conductivity disposed in the semiconductor substrate, wherein the fingers are located between the two second heavily doped regions of the second conductivity.
4. The electrostatic discharge protection device as claimed in claim 3, further comprising a pickup region of the first conductivity in the active region of the first conductivity such that the active region is biased via the pickup region.
5. The electrostatic discharge protection device as claimed in claim 1, wherein the two second heavily doped regions and the pickup region are connected.
6. The electrostatic discharge protection device as claimed in claim 1, wherein the first lightly doped region of the second conductivity is doped with phosphorous at a dosage of 1E12 to 1E13 cm−2.
7. The electrostatic discharge protection device as claimed in claim 1, wherein the second lightly doped region of the second conductivity is doped with phosphorous at a dosage of 1E12 to 1E13 cm−2.
8. An integrated circuit comprising an electrostatic discharge protection device, the electrostatic discharge protection device comprising:
- a multi-finger gate comprising a plurality of fingers mutually connected in parallel over an active region of a first conductivity;
- a first lightly doped region of a second conductivity in the active region between two of the fingers;
- a first heavily doped region of the second conductivity disposed in the first lightly doped region of the second conductivity; and
- a second lightly doped region of the second conductivity beneath and adjoining the first lightly doped region of the second conductivity, wherein the second lightly doped region of the second conductivity narrower than the first lightly doped region of the second conductivity.
9. The electrostatic discharge protection device as claimed in claim 8, wherein the active region of the first conductivity is a well region or a semiconductor substrate of the first conductivity.
10. The electrostatic discharge protection device as claimed in claim 8, further comprising two second heavily doped regions of the second conductivity disposed in the semiconductor substrate, wherein the fingers are located between the two second heavily doped regions of the second conductivity.
11. The electrostatic discharge protection device as claimed in claim 10, further comprising a pickup region of the first conductivity in the active region of the first conductivity such that the active region is biased via the pickup region.
12. The electrostatic discharge protection device as claimed in claim 8, wherein the two second heavily doped regions and the pickup region are connected.
13. The electrostatic discharge protection device as claimed in claim 8, wherein the first lightly doped region of the second conductivity is doped with phosphorous at a dosage of 1E12 to 1E13 cm−2.
14. The electrostatic discharge protection device as claimed in claim 8, wherein the second lightly doped region of the second conductivity is doped with phosphorous at a dosage of 1E12 to 1E13 cm−2.
15. An electrostatic discharge protection device, comprising:
- a multi-finger gate comprising a plurality of fingers mutually connected in parallel over an active region of a first conductivity;
- a double diffused drain (DDD) region of a second conductivity in the active region between two of the fingers; and
- a lightly doped region of the second conductivity beneath and adjoining the DDD region.
16. The electrostatic discharge protection device as claimed in claim 15, wherein the active region of the first conductivity is a well region or a semiconductor substrate of the first conductivity.
17. The electrostatic discharge protection device as claimed in claim 15, further comprising two heavily doped regions of the second conductivity disposed in the semiconductor substrate, wherein the fingers are located between the two heavily doped regions of the second conductivity.
18. The electrostatic discharge protection device as claimed in claim 17, further comprising a pickup region of the first conductivity in the active region of the first conductivity such that the active region is biased via the pickup region.
19. The electrostatic discharge protection device as claimed in claim 15, wherein the two heavily doped regions and the pickup region are connected.
20. The electrostatic discharge protection device as claimed in claim 15, wherein the lightly doped region of the second conductivity is doped with phosphorous at a dosage of 1E12 to 1E13 cm−2.
Type: Application
Filed: Jul 25, 2006
Publication Date: Jan 31, 2008
Patent Grant number: 7485905
Applicant: TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD. (Hsin-Chu)
Inventors: Feng-Chi Hung (Zhubei City), Jian-Hsing Lee (Hsinchu City), Hung-Lin Chen (Pingtung City), Deng-Shun Chang (Kaohsiung City)
Application Number: 11/459,650
International Classification: H01L 23/62 (20060101);